Selective switch mechanism for telephone or other systems



M. SETTER.

SELECTIVE SWITCH MECHANlSM FOR TELEPHONE OR OTHER SYSTEMS.

APPLICATION FILED JAN. 12. i905.v

1,317,597. PatentedSept. 30,1919.

6 SHEETS-SHEET THE COLUMBIA PLANOGRAPH co., WASHINGTON. D. c.

M SETTER.

SELECTIVE SWITCH MECHANISM FOR TELEPHONE OR OTHER SYSTEMS.

APPLICATION FILED JAN.12. I905- 6 SHEETSSHEET 2. E

W E w m m n :m 1M 4 1 7 WW w @W m w M 1 a 0 1 my M, SETTER.

SELECTIVE SWITCH MECHANISM FOP TELEPHONE OR OTHER SYSTEMS.

APPLICATION FlLE'D JAN-12.1905.

S? \Q NE M? win 554$.

THE cowamlb PLANOERAPII 50., WASHINGTON. D. c.

M. SETTER.

SELECTIVE SWITCH MECHANISM FOR TELEPHONE OR OTHER SYSTEMS.

APPLICATION FI LED JAN. I2.1905.

Patented Sept. 30, 1919.

SSHEE'IS-SHEET 4- 'M. SETTER.

SELECTIVE SWITCH MECHANISM FOR TELEPHONE OR OTHER SYSTEMS.

APPLlCATION FILED JAN. 12. I905- 1,317,597, PatentedSept. 00,1919.

6 SHEEISSHEET 5.

M. SETIER.

SELECTII/E SWITCH MECHANISM FOR TELEPHONE OR OTHER SYSTEMS.

flPPLICATION FILED JAN. 12. 1905.

1,317,597. Patentedsept. 30,1919,

GSHEETS-SHEET 6- suascmuns um:

I I IE Z E MICHAEL SETTER, OF CHICAGO, ILLINOIS,

ASSIG-NOR, BY MESNE ASSIGNMENTS, TO

AUTOMATIC ELECTRIC GOIVIPANY, A CORPORATION OF ILLINOIS.

SELECTIVE SWITCH MECHANISM FOR TELEPHONE OR OTHER SYSTEMS.

Specification of Letters Patent.

Application filed January 12, 1905. Serial No. 240,702.

To all whom it may concern:

Be it known that 1, MICHAEL Sn'rrnn, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Selective Switch Mechanism for Telephone or other Systems, of which the following is a specification.

My invention relates to automatic switches in general, but more particularly to automatic switches for use in telephone systems, and especially to the switches which are individual to the different subscribers.

Generally stated, the object of my invention is the provision of an improved, simplified and highly efficient automatic switch for selectively establishing connection with one of a number of trunk-linesthat is to say, any one which may be found idle or not in use at the time the switch is operated.

A special object is to provide an improved automatic selective switch, operatingon the step-by-step principle, and adapted to be allotted or made individual to a single subscriber, and adapted also, when set in operation by a singleelectrical impulse, to automatically select an idle trunk-line from among the different trunk-lines with which the switch as a whole is connected.

Another object is to provide an automatic switch of such character that the apparatus of an automatic telephone system may, as a whole, be substantially simplified and min dered more economical to install and maintain, but without in any way decreasing the efiiciency or limiting the service between subscribers.

It is also an object to provide certain. details and features of construction, and of improvei'nent in the forms of switches here tofore employed, tending to increase tle general efliciency and serviceability of automatic selective switching mechanism of this particular character.

To the foregoing and other useful ends, my invention consists in matters hereinafter described and claimed.

In the accompanying drawings, Fig. l is afront elevation of an automatic selective electrical switching mechanisn'i embodyithe principles of my invention.

' Fig.- 9) shows the same in side elevation? Fig. 3 is a view similar to Fig. 1, but showing the cover or casing removed, so as to expose to View the interior mechanism.

Fig. 4 is a side elevation of the parts and devices shown in Fig. 3, certain portions being shown in section, or broken away, for convenience of illustration.

Fig. 5 is a vertical section of the frame and mechanism shown in Fig. l.

Fig. 6 is a detail perspective of one of the switch-springs of the combined re lease and cut-off relay.

Fig. 7 is a perspective of another one of the switch-springs of the combined release and cutofi' relay.

F 8 is a perspective of a spring for operating the release-armature of the said combined release. and cut-off relay.

Fig. 9 is a detail side elevation, partly in section, of the said combined release and cut-off relay.

Fig. 10 is adetail view showing the three fingers of insulating material which serve as stops for the spring-wipers or brushes on the rotatable switch-shaft.

Fig. 11 is a perspective showing the release-armature, and the locking-clog normally carried thereby, of the said combined release and cut-off relay.

Fig. 12 is a perspective of the cut-offarmature of the said combined release and cut-off relay.

Fig. 13 is a perspective showing the armature, and the pawl carried thereby, of the rotary-magnet, 2'. 6., the magnet for producing a stcp-by-st'ep rotation of the rotatable switch-shaft.

Fig. 14; is a detail view showing one of the wipers or brushes of the rotary switch-shaft.

Figs. l5, 16, 17 and 18 show different positions of the step-by-step or ratchet mechanism for producing a step-by-step rotation of the said rotatable switch-shaft.

Fig. 19 is a fragmentary perspective showing a frame for mounting the switches, and showing an entire switch, and also different portions of other switches, mounted thereon.

Fig. 20 is a detail sectional view illustrating one of the bars upon which the switches are removably mounted, and showing the manner of fastening the same to the rackbars of the frame.-

Patented Sept. 30, 1919. i

Fig. 21 is an enlarged detail view, partly in section, showing the strip of contacts which is mounted on the frame and which engages corresponding contacts carried by the removable switch mechanism, and whereby the removable portion of the switch mechanism may be mounted in place or removed without the necessity of soldering connections or breaking any wiring.

Fig. 22 is a detail view of the said strip of contacts carried by the removable part of the switch mechanism.

Fig. 23 is a detail section on line 2323 in Fig. 22.

Fig. 24; is a detail section on line 2al -2et 1n Fig. 21.

Fig. 25 1s a diagrammatic view illustrating the circuits of the switching mechanism illustrated in the preceding views.

As thus illustrated, my invention comprises a plate or body 1 adapted to suitably support the relays and magnets and operative parts of the switching mechanism. In order that the relays and step-by-step mechanism may be removed as a unit from the supporting structure, whereon several of said switches may be mounted, the said plate or body 1 is preferably provided with grooved side portions 2 adapted to receive the edges of a pair of supportingbars 3, which latter may be mounted in either a ,vertical or horizontal position. In all of the figures, except Fig. 19, the switch, as a whole, is shown in a vertical position; but in Fig. 19 an arrangement is shown for mountin g the switches in a horizontal position. As a means of holding said plate or body in place, when properly adjusted upon the bars 3, each grooved portion 2 may be provided with an opening l adapted to receive lugs or projections 5 on the outer edges of the said supporting-bars. At its lower or outer end, the said plate or body 1 can be provided with a handle portion 6, waereby the removable switching mechanism may be handled or carried. Also, the said plate or body may be provided with hooks or lugs 7 adapted to engage openings 8 in the end wall of the cover or closure 9; it being also observed that the edges of said cover or closure are provided with lugs 10 adapted to engage openings 11 in the said plate or body. In this way, the removable portion of the switching mechanism is of a compact and practically incl'osed character; and as a further means of securing the switching mechanism in place, the bracket 12, which is secured to the rack-bar 13 of the supporting frame, is provided with lugs 1 adapted to bear upon the face or outer surface of the said plate or body 1. As shown, the bracket 12 is arc-shaped in form, and is provided on its under side with a. strip of contacts 15 mounted in insulation 16. Preferably, the inner ends of said contacts are bifurcated, as shown in Fig. 21, while their outer ends are adapted for makin solder connections. It will also be seen that severalv areshaped banks of contacts are mounted upon the bracket-plate 12, the cont-acts in each bank being insulated from each other, and the different banks being insulated from each other by arcshaped strips of insulation 17. These cont-acts all have their inner ends held in position to be engaged by the switching devices, and their outer ends adapted to be soldered to the different wires with which the switch is connected. As shown, these metallic contacts are all. secured together or clamped together and held in place by screws 18 and a clamping-plate 19, said screws extending through the superimposed layers of contacts and insulation, and engaging the threaded openings in the bracket-plate 12. As will hereinafter more fully appear, and as shown more clearly in Fig. 25, the first contacts in each bank are restin contacts, such as the contacts 20, 21, and 22, 23 of the innermost four banks, and the contacts 2%, 25 of the outermost two banks. In addition to these, the innermost four banks contain preferably, in each case, ten'additional. contacts, while the outermost two banks contain, in each case, only one additional contact. These additional contacts 26 and 27 in the outermost two banks are preferably arc-shaped, ane extend practically for the full length or range of the different banks. The contacts 28 and 29 of the innermost two banks are linocontacts, being adapted to be connected with trunk-lines running to other switches. The contacts 30 of the third bank are releaseeontacts, being adapted to be connected with additional trunk-line conductors leading to other switches. The contacts 31 of the fourth bank are private bank-contacts, being adapted for establishing guarding potential for busy trunks, in the usual and wellknown manner. When a trunk line is busy the corresponding contact 31 will be found grounded, and the individual switch will pass over it. The function of the contacts 26 and 27 will hereinafter more fully appear.

As illustrated, the strip of contacts 15, or jack-sprin s as they may be termed, includes seven of such contacts or springs. \Vith the circuit connections shown, the springs or contacts 82 and 33 are linesprings, being connected with opposite sides of the line running to the subscribers station. The functions of the remaining springs or contacts will hereinafter more fully appear, although it is obvious that these jack-springs or contacts may be utilized for any purpose for which they may be found suitable, and employed in making various circuit connectlons.

It will seen that the different bank contacts, and the said strip of contacts or jack-springs 15, are all mounted upon the frame or rack upon which the switch as a while is supported. In this way, the various wires can be soldered to the banlocontacts and the different jaclcsprings of the strip 15, thus permitting the removable portion of the switching apparatl'is to be inserted and removed without the necessity of breaking any wiring or any soldered connections. For example, the body-plate 1 has provided upon it, at its upper end, a strip of jaclo springs or contacts 34;, as shown in Figs. 5, 22 and Like strip 15, this strip 3 consists of suitable insulation in which the contacts or jack-springs are supported and insulated from each other. In. this case, the contacts or ack-springs 35 and 86 are linesprings, being adapted to engage the inner bifurcated end portions of the contacts or j rich-springs 82 and 83. It will be seen that the balance of the springs in this strip 3% are adapted to engage their respective jacksprings in the strip 15, and may be employed for any suitable or desired purpose. Preferably, the strip 34 is secured to the bodyplate 1 by means of screws 87. And with this arrangement it is obvious that the body plate 1, upon which are mounted the mag nets, relays and other operative parts of the switching mechanism, may be inserted. and withdrawn from the rack or supporting frame without the necessity of breaking any wiring or soldered connections. In fact, the said supporting frame or rack can be fully wired, and the jack springs and contacts mounted thereon all soldered to their respec tive wires before the removable switching mechanisms are inserted in place.

As a means whereby the subscriber may manipulate the switching mechanism, and make connection with any of the said bankcontacts which do not happen to be connected with a busy line, the said body-plate 1 is provided with a bracket 88, in which is supported a rotatable shaft 39 provided with a plurality of soalled wipers or brushes adapted to swing or oscillate from side to side, and thereby slide from one bank-contact to another. At its inner end, the said shaft 39 supported in an opening or hearing 40 provided in the said body-plate. A. ratchet-wheel 41 is mounted upon the inner end portion of the said shaft and provided with shoulders 4-2 and 43, the latter being adapted to normally engage a stop at provided on. sa d body-plate 1. It will be seen that the t e25 of the said ratchet-wheel extend only for a portion of the circumference thereof. and are adapted to be normally out of engagement with the lockingdog and the actuatingpawl 4:7. Preferably, the said looking-dog is mounted upon the body-plate 1 and pivoted at 48, and subto the pressure of the spring l -9, which latter tends, at all times, to force the lock ing-dog into engagement with the teeth of said. ratchet-wheel. Also, upon said rotatable shaft, there are provided wipers or brushes 50, 51, 52, 53, 54 and 55, shown more clearly in Fig. These wipers or brushes are each preferably of the form shown in Fig. 14-, being provided with an end or engaging portion 56, a body portion having an opening 57, and an arosha-ped slot 58, and a terminal portion The opening 57 is adapted to receive the rotatable shaft 39, while the arc-shaped slot 58 serves to, in effect, lengthen the engaging arm 56, thus giving it a suitable degree of flexibility, notwithstanding its comparatively short length. The terminal. portion 59 is, of course, adapted to be soldered to one of the wires or conductors of the switching apparatus. As illustrated, these wipers or brushes are all insulated from each other, and mounted upon a sleeve 60. Said sleeve is provided at one end with a shoulder, and is threaded at the other end. In this way, a nut 61 can be applied to the end of the sleeve and employed as a means for clamping the superimposed layers of insulation and flexible wipers or l'n-ushes firmly against said shoulder at the other end of the sleeve. It is obvious that any suitable means can he employed for keying or securing the said sleeve to the rotatable shaft 39, as, for example, the set-screw 62. At its upper end portion, and outside of the ln'acket 38. the said rotatable shaft 39 is provided with a clock-spring device 63, of any suitable, known or approved character. The function of this clock-spring device is, of course,

to yieldingly maintain the she in its normal position, and to then return the said shaft to its normal position as soon as the mechanism is released by the subscriber upon the termination of the conversation. Normally, said clock-spring device maintains the shoulder in engagement ith the stop 414.; and the rotation of the shaft, and

the movement of the wipers in the other direction, is limited by the stops carried by the backetplate 65, which latter is socured to the body-plate 1. lVith this ar- 5 rangement, the said wipers or brushes can be swung around and made to travel from one contact to the other in the di tl erent banks. and when the correct position is reached the dog will lock the shaft and for performing other incidental functions, includes but three electro-magnets, as shown more clearly in Fig. The electroanagnet A is used as a combined release and cutoff relay. lVith the circuit arrangement shown, the electro-magnet B is employed as a. line-relay, being also provided with a retainingcoil. The electro-magnet 0 serves in the capacity of what is commonly known as a rotary-magnetthat is to say, a magnet for producing the desired step-bystep rotation of the switelrsliaft. In order that it may accomplish both of its functions, the relay A is provided with an inner cut-oif-coil 66, and with an outer releasecoil 67, the coil 66 being of much higher resistance than the coil 67, as will hereinafter more fully appear. Also, with the arrangement shown, this relay A is provided with a cut-otharmature 68, and with a release armature 69. The said out ofl-armature is arranged inside of the r lease-arn'iature, and is provided with an arm 70 adapted to operate the switch-springs 71, 72, 73 and 74; it being observed that springs 72 and 74 are connected by insulation, so as to move in unison when raised from out of contact with the springs 'Ii 1 and 73. The release-armature 69 is provided with an arm 75 which is engaged by a spring 76. Preferably, the said spring engages the lower end portion 7'7 of adog 78, which latter is pivotally mounted upon the end portion of the arm 75. This dog 78 is, of course, actuated by the release-armature, and in addition to moving the pawlat? out of engagement with the ratchet-wheel, serves also to then retain the said pawl in its disengaged position; it being observed that the spring '76 is preferably secured to the arm 7 A spring 79, however, adapted to bear upon the upper edge of the arm 75, serves to keep the pawl 47 normally out of engagement with the ratchet-wheel, and to keep the armature 69 away from the magnet A. As shown, the pawl 47 is provided with a beveled portion 80 adapted to be engaged by the hook-shaped end portion of the dog 78. lVhen this dog 78 rises, it slips readily over the beveled outer surface of the portion 80, and then springs into place above the portion 80, so that it may then pull the pawl 47 downward immediately upon the deenergizing of the magnet A and th release of the armature 69. In Fig. 25, it will be observed that the diagrammatic representation is such that the release of the pawl at? from its ratchet-wheel occurs upon the energizing of the magnet A; but it will be readily understood that this is merely for convenience of illustration, and that in actual practice the release occurs upon the deenergizing of this magnet, and the consequent release of the armature 69. This result, namely, the release of the ratchet-wheel upon the de'enerratchet-wheel gizing of magnet. A, is accomplished by the construction shown in the other figures of the drawings, and in the manner explained.

The pawl 4:7 is, it will be seen, pivotally mounted upon the end of the arm 81, which latter is rigidly secured to, or made integral with, the armature 82 of the rotary-mag net C. A spring 83, secured to the arm 81, bears upon the lower edge of the pawl 57, and tends to keep the latter in engagement with the ratchet-wheel ll. A piece of insulation 8 secured to the arm 81, serves as a means whereby the armature 82, when attracted, separates the switch-springs 85 and 86, and thereby opens the circuit of the coil 87 of said rotary-magnet, as will hereiir after more fully appear. It will also be seen that the spring 86 is preferably of suliicient strength and tension to serve as the means for actuating the arm 81, and as the means whereby the latter causes. the pawl 47 to positively engage and rotate the secured to the rotatable switch-shaft 39. In other words, the spring 86 has a double function, so to speak, being used for opening and closing the circuit of the coil 87, and for actuating the step-bystep device for producing an intermittent rotary movement of the switch-shaft.

The coil 88 of the line-relay B is employed for energizing this relay at the will of the subscriber to whom the switching mechanism, as a whole, is allotted or made individual. The coil 89 of this line-relay is used as a retaining-coilthat is to say, as a coil for keeping the relay energized at a certain point in the operation of the switching mechanism, and at a time when the coil 88 will be out of circuit. Vi hen energized, the relay l3 attracts its armature 90, which latter is provided with an arm carrying a piece of insulation 91. This knob or piece of insulation 91 engages a spring 92, which tends normally, and at all times, to keep the armature in its retracted position. In addition to this mechanical function, however, the said spring 92 serves as a switchspring, being adapted to vibrate between the stationary switch-springs 93 and 94:, and being normally in contact with spring 93 and out of contact with spring 94-.

Now, as to the construction of these different electro-magnetic devices: Preferably, and as will be observed, each relay or magnetthat is to say, each electro-magnet and its allotted switch-springs and armature-is removable as a unit from the face or outer surface of the body-plate 1. Take the com bined release and cutoff? relay A for example. In this case, the magnet-core 95 is secured by a screw 96 to an L-shaped bracket-plate 97, the latter extending above the magnet for its full length, and thence downward between the end of the magnet and the body-plate 1. A screw 98 is employed for securing the bracket-plate 97, and the parts supported thereby, to the said body-plate .1. To the outer end of said L- shaped bracket-plate the armature 69 pivotally secured by means 01 pivots 99, one of which may be a screw adapted to be given any desired or necessary adjustment, and to be held in such adjustn'ient by a lock-nut 100. The springs 71, 72, 73 and 74 are mounted upon the top cl the bracket-plate 97 and secured in place by means of screws 101; it being observed that the said springs are separated from each other by strips of insulation 102, the springs 72 and 74 being preferably of the form or pattern shown in Fig. 0, and the springs 71 and 7 3 being preferably of the shape or design shown in Fig. 7 The movable switclrspiing shown in Fig. 6 has two parallel portions connected at their ends by a cross portion, one of said parallel portions being left free to bend or flex up and down, and thereby moved into and out oi? engagement with another spring, and the other parallel portion being pro vided with openings 103 adapted to receive the screws 101, and with a terminal portion 101- adapted to be soldered to a wire or other conductor. The stationary spring shown in Fig. 7 has a body portion provided with openings 105 adapted to receive the screws 101, and with a terminal portion 106 adapted to be soldered to a wire or other conductor; and the stationary spring is also provided on. its inner end with a laterally-proiecting or right-angled piece adapted to be engaged by the flexible portion of the spring shown in Fig. 6. \Vhen assembled in place, it will be seen that these springs and the interposed pieces of insulation are clamped in a superimposed condition upon the top of the bracket-plate 97 in such manner that the terminals 10% projectoutwardly in one di rection, while the terminals 106 proj outwardly in practically the opposite direction. A. clamping-plate 107 is engaged by the heads of the screws 101, and serves to clamp the superimposed springs and pieces of insulation in place; and the ends of said screws are adapted to engage threaded openings in the bracket-plate 97. At its outer end, the bracket-plate 97 is provided with a notch" adapted to receive tl e upper portion of the armature 68, and wherein this portion of the said armature pivotally mounted. Thus it will be seen that the piece of insulation 1.08, carried at the end of the arm 70, is adapted to engage the under side of spring 72, and to thus shift this spring and spring 7 1- simultaneously, the two springs being connected by the piece of insulation 109. hen attracted, the armature 68, with the arrangement shown, moves the springs 72 a: "l 74 out of engagement with the stationary SDTlDgS 71 and 73. The arms 7 5 and are practically parallel, and are also practically parallel with the flexible portions of 'tch-springs 72 and 74. In order that tare (38 may alone be attracted when the inner coil 66 is energized, this armature preferably somewhat lighter than the arnnrture 69. The actuating spring 79 is preferably secured to the right-angled sped 1' porti ng "p 110, which latter is i the bott so ui i. om of the bundle of switci rings. In this way, the spring 79 is adapted to bear upon the arm 7 5, which bodyplate 1. A screw 113 serves as a means for clamping the plate 112 to the said bodyplate 1. The armature 90 is pivotally mounted upon the outer end portion of the bracket-plate 112, preferably by means of a couple of pivots, whereof one is a screw 11% adapted to be locked in any desired or necessary adjustment by a lock-nut 115. The arm 116 of this armature is provided with the previously described piece of insulation 91, and is arranged to swing up and down close to one edge of the bracket-plate 112. The springs 92 and 94. are similar in shape to the ones shown in Fig. 6, while the spring 93 is similar in shape to the one shown in Fig. 7, with the exception that the terminals of these springs extend laterally in a direction more nearly at right angles to the body portions thereof. All of said springs, together with the interposed strips of: insulation 117, are clamped to the under side of the bracket-plate 112 by means of a clamping-plate 118 and screws 119. In addition, a ring or hook 120 is clamped to the bottom of said springs and strips of insulation. This ring or hook is preferably of some suitable insulating material, and is adapted to have wires or flexible conductors threaded through it, and thereby held against entanglement with any of the op erative parts of the switching mechanism. In this way, the relay 13 consists of a comparatively small and compact structure which is removable as a unit from the face of the bod plate 1. The rotary-magnet C is also of a unitary character, its magnet, springs and armature all being removable as a unit tron?! the face of the body-plate 1. The spring 85 similar in shape to the spring shown in Fig. 6, with the exception of the body portion and the terminal p0rtion, which are slightly different. The

spring 86 is also similar in shape to the spring shown in Fig. 6, but is preferably somewhat heavier and stronger, inasmuch as it constitutes the means for positively actuating the pawl 17, and for thereby rotating the switch-shaft. The magnetcore of the magnet (J is secured to an L-shaped bracket-plate 121, which extends along one side of the magnet, and thence between the end of the magnet and the face of the body-plate 1. Any suitable means may be employed for securing this bracket-plate to the said body-plate 1. The armature S2 is pivotally mounted upon the outer end oi the said bracket-plate 121 by means of pivoting means similar to those employed in connection with the other armature/S. Like the other armatures, it is provided with one pivot 122, consisting of a screw adapted to be locked in any desired adjustment by a lock-nut 123. This armature is provided with the previously mentioned arm 81, which carries the piece of insulation 8 1- adapted to operate the spring 86. This arm 81 is, it will be seen, adapted to swing in a horizontal plane immediately above the upper edge of the bracket-plate 121.

Thus it will be seen that the axes of the different electro-magnets are all parallel and horizontal, extending at right angles to the face of the body-plate 1. It will also be seen that the axes of all the armatures, except the armature 82, are parallel and horizontally disposed, extending at right angles to the axes of the electro-magnets. In the case of the relay C, however, the axis of its armature 82 extends vertically and at right angles to the axes of the other armatures and to the axes of the electromagnets.

In connection with the ring or hook 129 for the flexible conductors, it will be seen that the insulating strips for separating the wipers on the switch-shaft 39 are provided with ring portions 124-. These ring portions are associated with the terminals 59 of the said wipers, it being observed that half of these terminals project at one side of the said ring portions, while the other half project at the other side. In this way, connection of the wires or flexible conductors with the said terminals is greatly facilitated.

It is obvious, of course, that the electrical and mechanical construction thus provided may be found useful and desirable with circuit arrangements other than those illustrated in Fig. 25. vVith the parts connected as shown in this diagram, however, the operation, when the subscriber, to whom the switch as a whole is alloted, takes down the receiver and makes a call, would be as follows: The two sides of the line would be momentarily connected together, thereby establishing a circuit from ground G through contact 21 and wiper 51, through switch springs 7 1- and 73, and then through jackspring 32 to one side of the subscribers line, through the subscribers telephone apparatus, back on the other side of the line, through contact-springs 71 and 72, through wiper 50 and contact 20, and through coil 88 to the other pole of the battery K. This, of course, energizes the line-relay B, causing it to attract its armature, and in so doing to close a circuit from ground through contact 23 and wiper 53, through contact springs 92 and 94-, switch-springs 86 and 85, relay-coil 87, and then to the other pole of the battery. As relay C attracts its armature, it causes switch-springs and 86 to separate; and this, of course, causes the release of armature S2, and consequently a partial rotation of the switch-shaft by reason of pawl 7 being brought into engagement with the ratchet-wheel 11. This, it will be seen, is accomplished by reason of the pawl 47 being disengaged from the dog 78 as soon as armature 82 is attracted, and by reason of the consequent disengagement of the locking-dog 4:6. AS soon as this dog 4L6 is disengaged from the portion 125, it is then free to engage the ratchet-wheel 41, and to retain the latter against back rotation, while the actuating-pawl d? is again retracted by the energizing of relay G. Then, as soon as the relay C is deenergized, by the separation of the contacts 85 and 86, the portion 125 of the pawl 17 engages the ratchet-teeth 45 of the ratchet-wheel, and thereby rotates the switch-shaft one tooththat is to say, to an extent equal to the distance between two successive teeth. When this occurs, wipers 50, 51, 52, 53, and 55 are moved off "from their normal resting contacts and onto contacts, 28, 29, 30 and 31, and 26 and 27. As soon as this switching action is accomplished, s veral results inevitably follow: For example, wiper 54, which has been normally resting on contact 2's is moved into engagement with contact 27, which latter is connected to ground at G. This, of course, connects the jackspring 126 with ground, and establishes a guarding potential. at the contacts and other switches with which this jack-spring 126 is connected, by means of a socallcd private-normal; and in this way, any other subscriber, in attempting to make connection with the line-wires leading from springs 32 and 33, would receive the busy signal. Also, if contact 31 in the privatebank should be found busy, it will, of course, be connected to ground in the customary way by the switch using a multiple of this contact. In such case, the circuit completed will be from ground G through contact 31, through wiper 53, through contact-springs 92 and 94, through retaining coil 89 to the other pole or the battery; thus causing armature 90 to remain attracted even after the circuit has been broken through the line-coil S8 of the line-relay B by the movement oi the wipers 50 and ()1.

At this juncture, it will be seen that the relative arrangement of the contacts, and the construction of the coil and armature of relay B, and springs 92 and 94L, and wiper 58, must be such that the said armature will keep the said springs in contact during the time that said wiper passes from con Let 23 to contact 81; and also during the time that the said wiper passes from contact 31 to the next contact in the same level or bank, and so on throughout the range of travel or swing of the said wiper; and in this way, contact is constantly maintained between springs 92 and 94 until wiper 53 moves on to a contact which is not busy, and which is not, therefore, connected to ground. Moreover, the grounded connection resulting from contact between the wiper 53 and the busy contact 31 performs other "functions in addition t that oi" causing the armature of relay B to remain attracted. For example, it also furnishes current from switclrspring 9% through springs 86 and 85 to operate the rotary-magnet C, and thereby keep the stepby-step mechanism in motion as long as wiper 58 continues to remain in engagement with a busy contact. It must also be borne in mind that a circuit is closed from switch-spring 94L through wiper 55, contact 26, through the inner winding of relay A, thus causing it to attract its armature 68; and this, of course, breaks contact between springs 71, 72, 73 and 7d, and thereby cuts the wipers 50 and 51. (which latter form part of any talking circuit established by the switch) out of circuit with the subscribers linewires until the rotary motion of the switchshatt is terminated; and when the said shaft stops rotating, and brings the wipers into engagement with idle contacts in the banks, this connection will again be established for the reason that current will then no longer flow through coil 66 of the relay A.

hen said wipers reach a setv of contacts 0 nnected with a trunk-line, or other conuection not then in use, armature 90 will be released, and contact thus broken between springs 92 and 94 and reestablished between springs 92 and 93; and this, obviously, will establish a circuit from ground through wiper 53, through the contact 31 upon which the wiper is then resting, and thus establishing a guarding potential at all of the multiples of such contact, and thereby preventing some other subscriber from making connection with the same trunk-line or other connection. This having been. accomplished, it will be seen that the switch has not only picked out a pair of trunk-line conductors not then in use, having completed the con nection between ti e subscribers line-wires and these trunkline conductors through wipers 50 and 5-1, but has also made connection with any role; se-trunk, or other like conductor, connected with he particular contact 30 upon which the wiper 52 has been brought to rest; and one point of the normally open release -circuit having thus been closed by the individual switch herein shown and described, it is evident that, after the conversation is terminated, the switching mechanism may be restored by energizing coil 67 01 the relay A. This can be done, of course, in the usual and well-known manner, by establishing a ground at some other point in the release-circuit, so as to close a circuit from ground over the release-trunk and through the contact 30 and the wiper through the outer winding of relay A, and thence to the other pole of the battery; thus causing armature 69 to be attracted, thereby causing the 75 of such arn'iature to engage the end of the pivoted pawl 47. Upon the cessation of current through the relay A, the spring 79 then restores the armature 69 to its normal position, and in so doing causes the hook-shaped dog 78 to draw the pawl L7, and also the locking-clog &6, out of engz ment with the ratchet-wheel 4-1. This he ing been done, the clock-spring devire applied to the end of the switch-shaft then causes tl'ie latter to rotate in a backward dif" ion until it reaches its nornial position that is to say, until the shoulder 43 reenthe stop %4-, thus bringing all oil the wipers on the switch-shaft back into engagement with their normal or resting contacts. The restoration of the switch in this manner retistablishcs connection between the "private-normal jaclespring 1'26 and the resting contact 24lot the wiper 54, thus restoring the norn'ial connection existing between the said. jack-spring 120 and the negative pole oi the battery X, such connection including, of course, the inside winding or cutoff-coil 66 of the relay A. In this way, and by making a grounded connection with. the jack-spring 126, which can be done in any usual or desired manner by another subscriber attempting to call the subscriber to whom the individual switch now under consideration is allotted, a grounded circuit will instantly be closed, said circuit including the battery and the said cut-oft coil 6 of the relay A. Consequently, the bridge normally existing across the springs 32 and 33, whereby the subscriber whose l ne-xii 3- connect with these jacksprings may initiate the operation 0"? the switching mechanism, is opened up or cut oil by the relay A as soon as another subscriber secures connection with the line wires running from the jaCk-springs and 33 to the station of the subscriber to whom the switching mechanism shown in Fig. 25 is allotted; thus eliminating said bridge from the circuit during the time the subscribers are talking.

It will thus be seen that the switching mechanism, as soon as operated by the subscriber to whom, it is allotted, not only makes the desired trunk-line or other connection, but also establishes, through the medium oi the wiper 5i and the contact 27, such a guarding potential as will preclude seizure of the subscribers line by another subscriber; and also such a guarding potential, through the medium of the wiper 53 and the contact 31, as will prevent any other subscriber from making connection with the trunk-line conductors with which the switching mechanism, shown in Fig. 25, has succeeded in making connection. Again, it will be seen that the switch herein described and illustrated is capable, upon receiving only a single impulse, of automatically operating and remaining in operation until it picks out an idle trunk or other line connection. The step-by-step rotation of the switch-shaft is obtained by spring means, and the switch-shaft is restored to normal position by spring means; and a spring is also, as previously explained, employed for releasing the switch-shaft. In other words, the electro-ma-gnets are simply employed for attracting their respective armatures, the restoring springs for the armatures being relied upon for rotating the switch-shaft, and for releasing the switch-shaft after the conversation is terminated.

Obviously, with a simple yet eltective and efficient switch of the foregoing character, the so-eallcd first selectors, or other switches receiving the impulse or impulses representing the first digit or digits of the called number, may be greatly reduced in number, as with a switch of the foregoing character allotted to each subscriber it is not necessary that the usual first selector, or other similar switch, be allotted to each subscriber, it being possible, with my invention, to simply provide ten first selectors, for example, for each one hundred subscribers.

It will be understood that the trunks or trunk lines leading from the individual switch, such as the three-conductor trunk line T, may lean to selectors or connectors, or to any other apparatus for trunking or switching or connecting in accordance with the called number. In this way the switching or connecting done by the individual switch has no reference whatever to the called number, and is of a purely preliminary character. Each individual switch has a trunk-release circuit which includes the third conductor of any trunk line that may have been seized by the said switch, and this trunk-release circuit is controlled by means outside of the individual switch, but responsive to the hanging up of the subscribers receiver. Any of the well-known devices can be employed for closing the said trunk-release circuit back over the third conductor of the seized trunk line, when the subscriber hangs up his receiver. Furthermore, it will be seen that each individual switch is pro vided with jack springs adapted to be directly inserted in the ack springs on the support. In other words, the direct forward or horizontal insertion of the individual switch in place is sul'licient to bring its jack springs 23 into electrical engagement with the ack springs 0n the shelf or support. In this way the subscribers individual switches, or other automatic switches or suitable switch mechanisms, are easily adjusted in place. What I claim as my invention is 1. An automatic switching device comprising a rotatable switch-shaft, a ratchet device for giving said shaft a step-bystep rotary motion, a magnet mounted with its axis parallel with the axis of said shaft, a pivoted armature for said magnet, said armature having an arm connected *ith said ratchet device and thereby adapted when attracted to retract said ratchet device, a spring-switch device adapted to be opened by said arm when the armature is attracted, and also adapted upon the deenergizing oi. said magnet to restore said armature and thereby actuate the said ratchet device, a circuit controlled by said spring switch and including the winding of said magnet, and a source of electrical current and connections therefrom for operating purposes.

2. An individual switch for automatic telephone systems, comprising a combined release and cut-oil relay, said relay being provided with an inner cut-ol'l-coil and an outer release-coil, and with a release-armature and a cut-ofi-armature, both armatures being arranged at the same end of the magnet, but the cut-oitarmaturc being arranged between the magnet and the release-a-nnature, and a source of electrical current and connections therefrom for operating purposes.

3. An individual switch for automatic telephone systems, comprising suitably operated step-by-step switching mechanism, a pair of "line-terminals", a bridge normally existing across said line-terminals, a combined release and cut-off relay, said relay being provided with two armatures, together with means operated by one armature for opening or cutting of? said bridge, and means operated by the other armature for releasing said step-by-step mechanism, and a source of electrical current and connections therefrom for operating purposes.

4. An automatic switching device comprising step-by-step mechanism and a normally bridged coil, a relay provided with two coils of different energizing capacity, two armatures for said relay, one armature being adapted to respond to a currentflow in one coil, and both arn'iatures being adapted to respond to the current-flow in the other coil, means whereby one armature when attracted cuts off or opens up the said bridge, means whereby the other armature when attracted releases the said step-by-step mechanism, and a source of electrical current and connections therefrom for operating purposes.

5. An automatic switching device comprising a rotatable switch-shaft, a ratchetwheel on said shaft, a pawl for operating said ratchet-wheel, a magnet provided with a pivoted armature, said armature being connected with said pawl, a spring-switch device for restoring said armature and ac tuating said pawl, the said magnet, armature spring-switch and pawl being remov able as a unit from the balance of the structure, and a source of electrical current and connections therefrom for operating purposes.

6. An automatic switching apparatus comprising a plurality of banks of contacts removable as a unit from the apparatus, a plurality of wipers adapted to engage said contacts and also removable as a unit from the apparatus, an electro-magnetic device for giving said wipers a step-by-step rotary movement, said device being removable as a unit from the apparatus, a line-relay controlling the circuit of said electro-magnetic device and removable as a unit from the apparatus, a combined release and cut-off relay removable as a unit from the apparatus, said last-mentioned relay having two armatures, means whereby one of said armatures when attracted cuts off the said line-relay, means whereby the other arm a ture when attracted releases the means for operating the said wipers, and a source of electrical current and connections therefrom for operating purposes.

7. In an automatic switching device, a line-relay removable as a unit from the device as a whole, said line-relay having a line-coil and a retaining-coil, a battery having one pole grounded and the other connected between the two coils, said relay having three switch-springs and an armature for operating the same, one of said springs being normally in contact with the second spring and normally out of contact with the third spring, and a source of electrical current and connections therefrom for operating purposes.

8. An individual switch for automatic telephone systems, comprising a combined release and cut-off relay, said relay having two coils of different energizing capacity, and also two a-rmatures, one of said aianatures being more responsive than the a source of electrical current and connections therefron'i for operating purposes.

9. The combination of a pair of horizontal supports, a pair of cross-bars having their ends mounted upon said supports, a bracket-plate on one of said supports, jacksprings carried by said bracket-plate, banks of switch-contacts also carried by said bracket-plate, a step-by-step mechanism provided with a body-plate adapted to removably engage said cross-bars, and provided also with jack-springs and wipers adapted to engage the jack-springs and contacts car ried by the said bracket-plate, and a source of electrical current and connections there from for operating purposes.

10. An individual switch for automatic telephone systems, comprising a rotatable switch shaft, means for controlling the operation of said shaft, said means comprising three electromagnets the axis of which are all parallel with the axis of the said shaft, arc-shaped banks of trunk terminals adapted to be engaged by wipers carried by said shaft, and automatic means for causing said wipers to pass over the busy terminals and stop on idle terminals, the said shaft and magnets being organized into a unitary structure which is structurally distinct from the said banks of trunk terminals, whereby the said unitary structure may be readily removed without removing the said banks.

11. In a system having a subscribers line, a nonnumerical trunking switch for said line including a pair of line wipers, a switch controlling the connection to said wipers, step-by-step mechanism for operating said wipers, an electromagnet, means operated by the magnet for releasing said mechanism to restore the same to normal condition, means controlling said switch and operated by said magnet, and a source of electrical current and connections therefrom for operating purposes.

12. A non-numerical trunk selecting switch mechanism comprising a pair of line wipers, a pair of line conductors connecting a subscribers station to said line wipers, a release mechanism, a release magnet for operating'said release mechanism and control ling the connection from said station to said wipers, trunk terminals to be seized by said wipers and a source of electrical current and connections therefrom, for operating pur poses.

13. A non-numerical trunk selecting switch mechanism comprising a pair of line wipers, a pair of line conductors connecting a subscribers station to said line wipers, a controlling bridge across said line conductors, and a bridge out off relay provided also said mechanism to normal condition. and

controlled by said relay.

14. In a switching mechanism for automatic telephone systems, the combination with albase comprising a stationary portion and .arelatively movable part guided there on, of a bank of terminal contacts mounted on the stationary, portion, a movable element mounted on the movable part of the base and cooperating with said contacts, mechanism for operating it also supported on said movable part of the base and a support adapted to receive the element when disengaged from the bank of contacts.

15. In a. switching, mechanism for automatic telephone systems, the combination with a row of terminal contacts and a movable contact element adapted to cooperate therewith, of a two-part base, one part being substantially of a U-shape and having supported thereon the row of terminal contacts and the other part being formed to slip in to the usshaped portion, the two parts having cooperating guides to insure the alinement of the movable element. with said row of contacts when the parts are placed togetl'ier, and means for operating said movable element carried on the movable part of said base.

16. In a switching mechanism for automatic telephone systems, the combination withterminal cont-acts arranged in a row, and a stationary support therefor, a movable element cooperating with said contacts, and a projection cooperating withsaidelement and arrangedin alinement with the last contact of said row and mechanism for operatingthe element, of a base plate guided on the support and detachable therefrom on which said element, projection and operating mechanism are mounted;

17. In a, switching mechanism for automatic telephone systems, the combination with a plurality of terminal contacts arranged in an arc-shaped row-and an underlying support provided with parallel ways, of a base plate detachably connected to the support and guided by said ways in its movements toward and'from the support, a revoluble element j ournaled on the plate and adapted to cooperate with said contacts and mechanism for operating it also carriedon the plate.

18. In a switching mechanism, for automatic telephone systems, the combination with a plurality of terminal contacts arranged in an arc-shaped row, a revoluble element cooperating therewith and means for advancing it progressively, of a projection adapted to support the element when it has passed beyond the last terminal, a retaining device for holding it in operated position, a support for the row of terminals, a base plate carrying the remaining parts, and guides between the support and base for insuring the alinement of the movable element with the row of terminals.

19. In an automatic switch for telephone exchanges, a series of contacts in circular re lation a concentrically mounted arm sweeping over said contacts, said contacts and arm being located on a two part base, one sup porting the contacts and the other the arm, and a support on one part to receive the arm when said part is disengaged from the other part.

20. In an automatic switch for telephone exchanges, a series of contacts in circular relation and a. concentrically mounted arm sweeping over said contacts, a two-part base on which said arm is located one part supporting the contacts and the other part supporting the arm, electromagnetic devices for moving said arm, and laterally-arranged plug and socket connections on the respective parts of the base adapted to form a part of the circuit for said electromagnetic devices, said plug and socket connections being arranged in parallelism with the direction of movement of said movable base.

21. In an automatic switch for telephone exchanges, a row of stationary bank or ter minal contacts, a movable contact element to cooperate therewith, and an electromagnetic mechanism for advancing it progressively over said contacts, a base movable relatively to the bank support and carrying the movable element and its operative mechanism, and plug and socket connections between said movable base and the stationary bank support to form a part of the circuit for the operating mechanism, said plug and socket connections a being arranged in parallelism with the direction, of movement of said movable base.

22. In a switching mechanism for automatic telephone systems, the combination with a support comprising parallel side portions and a connecting rear bar, a plurality of terminal contacts mounted on the sup port, and a baseplate guided between the side portions of the support, of a movable element mounted on the plate and cooperating with the terminals, andelectromagnetic devices for operating it, circuit elements for the latter and terminals for said elements mounted on the base, of line operating circuit terminals arranged on the support'and cooperating with the circuit terminals on the base.

23. A switch for automatic telephone exchanges comprising a two-part base plate or support, one of said parts being formed of a yoke or U-shape' and having a circular row of contacts mounted upon said yoke-shaped portion, the other part 01": said base being fitted to and movable in relation to the yokeshaped portion and carrying thereon a con tact arm and spindle mounted in a bridge in front of the circular contacts, actuating magnets for said contact arm also mounted on said movable base part, and means for guiding said movable portion into and out of adjustment with the stationary yokeshaped portion to cause said movable element to aline with said circular contacts.

24. An automatic trunk selecting switch comprising a relay having a plurality of windings, a plurality of armatures for said relay, the said arinatures controlling the operation of said trunk selecting switch, means for closing an energizing circuit through one of said windings to operate both of said armatures, and means for closing an energizing circuit through another of said Windings to operate only one of said armatures,

and means for extending a call from said automatic trunk selecting switch.

25. An automatic trunk selecting switch, a relay for said switch, a plurality of Windings for said relay and a plurality of armatures controlled by said relay, means for closing a circuit through one winding to operate only one of said armatures and means for closing a circuit through another of said windings to operate a plurality of said armatures, and means controlled by said armatures for operating said automatic trunk selecting switch substantially for the purposes set forth.

Signed by me at Chicago, Cook county, Illinois, this 30th day of December, 1904.

MICHAEL SETTER. Witnesses:

W. LEE CAMPBELL, R. C. GIFFORD.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. G. 

